Methods, systems, and devices for a motor control system

ABSTRACT

Systems, devices, and methods for controlling a motor are disclosed. A method may include determining a rotational direction of a motor from a pair of quadrature signals sent to a microprocessor. The method further includes adjusting an internal count stored in the microprocessor at each edge of each of the pair of quadrature signals. The method further includes adjusting an external count stored in the microprocessor and transmitting an interrupt to a main controller after the first phase signal and the second phase signal have transitioned through each combinational logic state in one of a forward rotational direction and a reverse rotational direction. The method further includes transmitting a signal comprising the rotational direction of the motor and the external count from the microprocessor to a main controller.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 12/256,687,filed Oct. 23, 2008, pending, which will issue as U.S. Pat. No.8,115,427 on Feb. 14, 2010, the disclosure of which is herebyincorporated herein by this reference in its entirety.

TECHNICAL FIELD

Embodiments of the present invention relate generally to motor controlsystems, devices, and methods and more specifically to motor controlsystems, devices, and methods for controlling rotational direction of amotor, dynamic braking of the motor, and providing accurate position andcontrol of a movable partition or door driven by the motor.

BACKGROUND

Motor relay arrangements in an H-bridge configuration are conventionallyused to control Direct Current (DC) motor direction. In its basic form,an H-bridge circuit typically includes four relays. On one side of themotor, a first relay connects a first motor terminal to a power sourceor an open circuit and a second relay connects the first motor terminalto ground or an open circuit. On the other side of the motor, a thirdrelay connects a second motor terminal to a power source or an opencircuit and a fourth relay connects the second motor terminal to groundor an open circuit. The H-bridge operates to cause current to flowthrough the motor, and cause forward rotation by energizing the firstrelay and the fourth relay, which causes current to flow through thefirst relay, through the motor from the first motor terminal to thesecond motor terminal, then to ground through the fourth relay.Similarly, to cause a backward rotation, the second relay and the thirdrelay are energized, causing current to flow through the third relay,through the motor from the second motor terminal to the first motorterminal, then to ground through the second relay. Unfortunately, if thewrong combination of relays is energized, too much current may flowthrough the relays resulting in various problems including, for example,damage to the circuit, the motor, or both.

In addition, conventional motor control systems may exhibit deficienciesrelated to positional accuracy and control of a motor. FIG. 1illustrates a timing diagram having quadrature signals (i.e., a firstphase signal A and a second phase signal B) generated from an encoderwithin a motor control system. As known by one having ordinary skill inthe art, if the first phase signal A leads the second phase signal B,then the direction of an associated motor is deemed to be positive orforward. Conversely, if the first phase signal A trails the second phasesignal B, then the direction of the motor is deemed to be negative orreverse. As illustrated, during time period 270 (i.e., when signal B istrailing signal A), at each rising and falling edge of signal A andsignal B, a count pulse 262 occurs and a position count value 264 isincremented. Similarly, during time period 280 (i.e., when signal A istrailing signal B), at each rising and falling edge of signal A andsignal B, a count pulse 262 occurs and a position count value 264 isdecremented. As such, signal A and signal B together may be indicativeof a rotational direction of a motor and position count 264 may beindicative of a position of the motor.

Additionally, in conventional motor control systems, at each rising andfalling edge of either signal A or signal B, an encoder may send aninterrupt and quadrature signals A and B to a controller. Upon receiptof quadrature signals A and B, the controller may determine a rotationaldirection of an associated motor. Additionally, the controller maydetermine a reference position of the motor by counting each rising andfalling edge of signals A and B. With continued reference to FIG. 1, atime at which an interrupt is sent is depicted by interrupt events 260(i.e., at the rising and falling edges of signal A). As shown in FIG. 2,during a first time period 470, signal B and signal A are bothtransitioning, signal B trails signal A and, therefore, an associatedmotor is moving in a forward or positive rotational direction.Conversely, during a second time period 480, neither signal A nor signalB are transitioning, and therefore, the associated motor is not in arotational mode. Although the motor is not operating in a rotationalmode during time period 480, the motor control system may experiencevibrations which may cause false edges 266 in a signal (i.e., signal A).Accordingly, at each false edge 266, interrupt and quadrature signalswith the false edge may be sent to the controller. As a result, aposition count determined by the controller may be incorrect and theaccuracy of the motor control system may be decreased.

Furthermore, as understood by one having ordinary skill in the art,sending an interrupt to a controller at each rising and falling edge ofeither signal A or signal B may be demanding on the controller.Moreover, in conventional motor control systems, an interrupt controlconfigured to receive an interrupt may also be configured to receivecommunication signals. Therefore, when an interrupt control is busyhandling a communication signal, attention to an interrupt signal may bedelayed resulting in inaccurate position counts and decreased accuracyof the motor control system.

A need exists to control a DC motor in both the forward rotationaldirection and the reverse rotational direction, and enable dynamicbraking of the motor. Moreover, a need exists to improve the positionalaccuracy and control of a motor control system.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a motor control circuit for controllingthe rotational direction of a motor while enabling dynamic braking andproviding additional improvements and advantages over the prior art.

In one embodiment of the present invention, a method of controlling amotor is provided. The method includes determining a rotationaldirection of a motor from a pair of quadrature signals sent to amicroprocessor. The method further includes adjusting an internal countstored in the microprocessor at each edge of each of the pair ofquadrature signals. The method also includes adjusting an external countstored in the microprocessor and transmitting an interrupt and a signalindicating the rotational direction of the motor and the external countfrom the microprocessor to a main controller. Adjusting the externalcount and transmitting the interrupt occurs after the first phase signaland the second phase signal have transitioned through each combinationallogic state in one of a forward rotational direction and a reverserotational direction.

In another embodiment of the present invention, a motor control deviceis provided. The device includes a microprocessor configured to receivea pair of quadrature signals from an encoder operably coupled to amotor. The microprocessor is further configured to output a signalindicative of a direction of the motor and a position of the motor to amain controller operably coupled thereto in response to an interruptevent. The microprocessor is also configured to output a plurality ofcontrol signals. The device further includes a motor control circuitoperably coupled to the microprocessor and comprising a plurality offield effect transistors. The motor control circuit is configured tocontrol an operation of the motor in response to receiving the pluralityof control signals from the microprocessor.

Another embodiment of the present invention may include a motor controlsystem including a motor and a motor control device such as the motorcontrol device described above. In one embodiment, the motor may includea direct current (DC) motor rated at approximately 14 volts or higher.In another exemplary embodiment, the motor may include a DC motor ratedat approximately 24 volts.

The system may include additional components depending, for example, onthe intended application of the motor. For example, in one embodimentthe motor may be operably coupled to a portion of a movable partition inorder to deploy and retract or otherwise displace the partition. Such apartition may include, for example, a folding or accordion-style doorhaving a plurality of hingedly coupled panels. The partition may beconfigured as a fire barrier in one particular example. Of course, thesystem may include other components and be configured for otherapplications as will be appreciated by those of ordinary skill in theart.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a timing diagram including quadrature signals indicative of arotational direction of an associated motor and a count indicative of aposition of the motor in a conventional motor control system;

FIG. 2 is another timing diagram including quadrature signals of aconventional motor control system;

FIG. 3 is a block diagram of a motor control system having a motorcontrol board including a processor and motor control circuit, inaccordance with an embodiment of the present invention;

FIG. 4 is a circuit diagram of a motor and a motor control circuit,according to an embodiment of the present invention; and

FIGS. 5A and 5B are timing diagrams including quadrature signals,internal counts, and external counts, according to an embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, circuits may be shown in block diagramform in order not to obscure the present invention in unnecessarydetail. Conversely, specific circuit implementations shown and describedare examples only and should not be construed as the only way toimplement the present invention unless specified otherwise herein.Additionally, block definitions and partitioning of logic betweenvarious blocks is exemplary of a specific implementation. It will beappreciated by those of ordinary skill in the art that the presentinvention may be practiced by numerous other partitioning solutions. Forthe most part, details concerning timing considerations and the likehave been omitted inasmuch as such details are not necessary to obtain acomplete understanding of the present invention and are within theability of persons of ordinary skill in the relevant art.

The terms “assert” and “negate” are respectively used when referring tothe rendering of a signal, status bit, or similar apparatus into itslogically true or logically false state. If the logically true state isa logic level one, the logically false state will be a logic level zero.Conversely, if the logically true state is a logic level zero, thelogically false state will be a logic level one.

The term “bus” is used to refer to a plurality of signals or conductors,which may be used to transfer one or more various types of information,such as data, addresses, control, or status. Additionally, a bus or acollection of signals may be referred to in the singular as a signal.Some drawings may illustrate signals as a single signal for clarity ofpresentation and description. It will be understood by a person ofordinary skill in the art that the signal may represent a bus ofsignals, wherein the bus may have a variety of bit widths and thepresent invention may be implemented on any number of data signalsincluding a single data signal.

As used herein, the terms “rotating the motor,” effecting, causing, orinducing “rotation” of the motor, or a “rotational mode” of the motor,refer to the relative rotational movement between the components of amotor such as a rotor and stator.

Additionally, as used herein, the term “each combinational logic state”refers to each binary combinational logic state of two transitioningsignals. More specifically, “each combinational logic state” of twotransitioning signals generated from a forward rotating motor wouldcomprise “00,” “10,” “11,” and “01.” Similarly, “each combinationallogic state” of two transitioning signals generated from a reverserotating motor would comprise “00,” “01,” “11,” and “10.”

FIG. 3 illustrates a motor control system 100 including a microprocessor200 and a motor control circuit 120 operably coupled to a motor 400.Microprocessor 200 may be any suitable microprocessor and may includepulse width modulation (PWM) control 230. Microprocessor 200 may beoperably coupled to motor control circuit 120 via bus 250 and interruptline 270. According to an embodiment of the present invention,microprocessor 200 may be a processor dedicated to motor control circuit120. Therefore, in this embodiment, microprocessor 200 and motor controlcircuit 120 may be located together on a motor control device 234, suchas a motor control board. Motor control system 100 may also include anencoder 210 including one or more sensors (not shown) and a maincontroller 220. Encoder 210 and main controller 220 may be operablycoupled to microprocessor 200 via respective buses 261 and 240.

The motor control system 100 of the present invention may be used tocontrol motor 400 in association with a variety of applications. As anexample, in one embodiment, the motor control system 100 may be used tocontrol a motor shaft of movable door or a movable partition such as isdescribed in U.S. Pat. No. 6,662,848 entitled AUTOMATIC DOOR AND METHODOF OPERATING SAME, attached hereto as Appendix A. Of course, numerousother applications are contemplated as will be appreciated by those ofordinary skill in the art.

Main controller 220 may be any suitable controller and may be configuredto monitor the state of a movable device (e.g., a movable door or amovable partition), monitor other aspects related to the control of themovable device, and thereby operate the movable device under a definedset of parameters or rules. Main controller 220 may be furtherconfigured to transmit one or more control signals via bus 240 tomicroprocessor 200 related to an operation of the movable device, suchas, for example only, an “open” operation signal, a “close” operationsignal, or a “brake” operation signal.

In response to receiving an “open” control signal from main controller220, microprocessor 200 may be configured to transmit a plurality ofcontrol signals to motor control circuit 120 to cause the motor torotate in a first rotational direction. Similarly, in response toreceiving a “close” control signal from main controller 220,microprocessor 200 may transmit a plurality of control signals to motorcontrol circuit 120 to cause the motor to rotate in a second rotationaldirection. Furthermore, in response to receiving a “brake” controlsignal from main controller 220, microprocessor 200 may be configured totransmit a plurality of control signals to motor control circuit 120 tocause rotation of the motor to cease in either direction.

FIG. 4 depicts a circuit diagram of motor 400 and motor control circuit120. Motor control circuit 120 includes a first switching device Q1, asecond switching device Q2, a third switching device Q3, and a fourthswitching device Q4. For example only, and not by way of limitation,first switching device Q1, second switching device Q2, third switchingdevice Q3, and fourth switching device Q4 may each comprise field effecttransistors (FETs). Additionally, for example only, first switchingdevice Q1 and second switching device Q2 may comprise p-channel devicesand third switching device Q3 and fourth switching device Q4 maycomprise n-channel devices. As illustrated in FIG. 4, a drain of firstswitching device Q1 is operably coupled to a power source 102 and a gateof first switching device Q1 is operably coupled to a close_high signal170. Power source 102 includes a voltage suitable for driving a DC motorrated at 12 volts DC or higher, such as a 24 volt DC motor. Moreover, adrain of second switching device Q2 is operably coupled to power source102 and a gate of second switching device Q2 is operably coupled to anopen_high signal 160. The sources of first switching device Q1 andsecond switching device Q2 are operably coupled to the drains of thirdswitching device Q3 and fourth switching device Q4, respectively. Thesources of third switching device Q3 and fourth switching device Q4 areeach operably coupled to a ground voltage 104. Furthermore, a gate ofthird switching device Q3 is operably coupled to an open_low signal 160′and a gate of fourth switching device Q4 is operably coupled to aclose_low signal 170′.

Motor 400 includes a first motor terminal 410 operably coupled to afirst node 430 located between the source of first switching device Q1and the drain of third switching device Q3. Motor 400 also includes asecond motor terminal 420 operably coupled to a second node 440 locatedbetween the source of second switching device Q2 and the drain of fourthswitching device Q4. Motor 400 may include a DC motor which, as will beappreciated by those of ordinary skill in the art, may include astator-rotor combination or a commutator-armature combination configuredto effect rotational motion of an output component such as a shaft. Inone particular embodiment, the present invention may be practiced with amotor rated at 12 volts DC or higher, such as a 24 volt DC motor,although motors of other voltages may be utilized with the presentinvention.

In operation, motor control circuit 120 may be thought of as operatingin a dynamic braking mode when open_high signal 160 and close_highsignal 170 are each asserted and open_low signal 160′ and close_lowsignal 170′ are each negated. Motor control circuit 120 may also operatein a dynamic braking mode when open_high signal 160 and close_highsignal 170 are each negated and open_low signal 160′ and close_lowsignal 170′ are each asserted. Furthermore, the motor control circuit100 may be thought of as operating in a rotational mode when close_highsignal 170 and close_low signal 170′ are each asserted and open_highsignal 160 and open_low signal 160′ are each negated. Motor controlcircuit 100 may also operate in a rotational mode when open_high signal160 and open_low signal 160′ are each asserted and close_high signal 170and close_low signal 170′ are each negated.

In the rotational mode, the motor control circuit 120 may cause themotor 400 to rotate in a first rotation direction or in a secondrotation direction, depending on the state of open_high signal 160,close_high signal 170, open_low signal 160′, and close_low signal 170′.In the rotational mode, motor 400 is enabled to rotate because firstmotor terminal 410 is operably coupled to power source 102 and secondmotor terminal 420 is operably coupled to ground voltage 104, or viceversa. More specifically, motor 400 may rotate in the first rotationdirection if open_high signal 160 and open_low signal 160′ are eachasserted and close_high signal 170 and close_low signal 170′ are eachnegated. The first rotation direction is enabled because the assertedopen_high signal 160 causes second switching device Q2 to conduct, andthe asserted open_low signal 160′ causes third switching device Q3 toconduct. Similarly, the negated close_high signal 170 and the negatedclose_low signal 170′ prevent respective first and fourth switchingdevices Q1 and Q4 from conducting. As a result, the second motorterminal 420 connects to power source 102 and the first motor terminal410 connects to ground 104, which may cause motor 400 to rotate in thefirst rotation direction.

On the other hand, the motor 400 may rotate in the second rotationdirection if the open_high signal 160 and open_low signal 160′ are eachnegated and the close_high signal 170 and close_low signal 170′ are eachasserted. The second rotation direction is enabled because the assertedclose_high signal 170 causes first switching device Q1 to conduct, andthe asserted close_low signal 170′ causes fourth switching device Q4 toconduct. Similarly, the negated open_high signal 160 and negatedopen_low signal 160′ prevent respective second and third switchingdevices Q2 and Q3 from conducting. As a result, the first motor terminal410 connects to power source 102 and the second motor terminal 420connects to ground voltage 104, which may cause motor 400 to rotate inthe second rotation direction.

To operate in the dynamic braking mode, either open_high signal 160 andclose_high signal 170 are each negated and open_low signal 160′ andclose_low signal 170′ are each asserted, or open_high signal 160 andclose_high signal 170 are each asserted and open_low signal 160′ andclose_low signal 170′ are each negated. With open_high signal 160 andclose_high signal 170 each negated and both open_low signal 160′ andclose_low signal 170′ asserted, neither first switching device Q1 norsecond switching devices Q2 is conducting, third switching device Q3 andfourth switching device Q4 are both conducting and, therefore, firstmotor terminal 410 and second motor terminal 420 are each connected toground 104. On the other hand, with open_high signal 160 and close_highsignal 170 both asserted and both open_low signal 160′ and close_lowsignal 170′ negated, neither third switching device Q3 nor fourthswitching device Q4 are conducting, first switching device Q1 and secondswitching device Q2 are both conducting and, therefore, first motorterminal 410 and second motor terminal 420 are each connected to powersource 102.

As will be appreciated by one having ordinary skill in the art, pulsewidth modulation control 230 (see FIG. 3) may be configured to generatethe control signals sent from microprocessor 200 to motor controlcircuit 120 to allow for variable speed control of motor 400. Forexample, control of motor 400 implementing pulse width modulation mayallow motor 400 to start and stop slowly and, therefore, reduce wear andtear on motor 400 and motor control system 100.

With reference to FIGS. 3, 5A, and 5B, encoder 210 may be coupled tomotor 400 and may be configured to output quadrature signals (i.e., afirst phase signal A and a second phase signal B) correlated to therelative position between the rotor and stator within motor 400. Asdescribed above, if the first phase signal A leads the second phasesignal B, then the direction of an associated motor is deemed to bepositive or forward. Conversely, if the first phase signal A trails thesecond phase signal B, then the direction of the motor is deemed to benegative or reverse. According to an embodiment of the presentinvention, upon receipt of quadrature signals A and B, microprocessor200 may be configured to determine a rotational direction of the motorand track a position of the motor by either incrementing an internalincrement count 462 at each combinational logic state (i.e., “00,” “10,”“11,” and “01”) in a forward rotational cycle, as shown in FIG. 5A ordecrementing an internal decrement count 462′ at each combinationallogic state (i.e., “00,” “01,” “11,” and “10”) in a reverse rotationalcycle, as shown in FIG. 5B.

Microprocessor 200 may also be configured to increment or decrement anexternal count 464 after completion of a complete cycle of first phasesignal A and second phase signal B (i.e., after first phase signal A andsecond phase signal B have transitioned through each combinational logicstate, “00,” “10,” “11,” and “01” for a forward rotation or “00,” “01,”“11,” and “10” for a reverse rotation). Additionally, according to anembodiment of the present invention, microprocessor 200 may beconfigured to output an interrupt and a signal indicating the rotationaldirection of the motor and external count 464 to main controller 220. Incontrast to prior art motor control systems described above,microprocessor 200 may be configured to output the interrupt to maincontroller 220 after completion of a complete cycle of first phasesignal A and second phase signal B (shown by interrupt events 460),(i.e., after first phase signal A and second phase signal B havetransitioned through each combinational logic state, “00,” “10,” “11,”and “01” for a forward rotation or “00,” “01,” “11,” and “10” for areverse rotation).

Stated another way, upon receipt of quadrature signals A and B fromencoder 210, microprocessor 200 may determine a rotational direction ofan associated motor and monitor a position of the motor by maintaininginternal increment count 462 and internal decrement count 462′.Furthermore, microprocessor 200 may, upon a completed transition througheach combinational logic state of signal A and signal B in onedirection, increment or decrement external count 464 accordingly, andsend an interrupt to main controller 220. Thereafter, a signal is sentto main controller 220 identifying the rotational direction of the motorand the external count 464, which is indicative of the position of themotor. Because external count 464 is not modified and an interrupt isnot sent until after completion of each transitional state in a forwardor reverse direction, main controller 220 will receive less interruptsand will handle less transitional states than a controller in prior artsystems. Consequently, the processing load on main controller 220 may bereduced in comparison to prior art systems. Furthermore, by modifyingexternal count 464 and sending an interrupt only after completion ofeach combinational logic state, any vibrations experienced by the motorcontrol system which may cause false edges will not trigger undesiredinterrupt or undesired count increments or count decrements.

Although, in the embodiments described above, microprocessor 200 isconfigured to output the rotational direction of the motor and externalcount 464 to main controller 220 after completion of a complete cycle offirst phase signal A and second phase signal B (shown by interruptevents 460). Embodiments of the invention are not so limited. In anotherembodiment of the present invention, main controller 220 may beconfigured to send a signal to microprocessor 200 requesting a status ofthe rotational direction of motor 400 and/or the position of motor 400.Upon receipt of the signal, microprocessor 200 may transmit a signalindicating the rotational direction of the motor and/or external count464 to main controller 220.

While the present invention has been described herein with respect tocertain preferred embodiments, those of ordinary skill in the art willrecognize and appreciate that it is not so limited. Rather, manyadditions, deletions, and modifications to the preferred embodiments maybe made without departing from the scope of the invention as hereinafterclaimed. In addition, features from one embodiment may be combined withfeatures of another embodiment while still being encompassed within thescope of the invention as contemplated by the inventors.

1. A motor system, comprising: a motor; a motor control circuit operablycoupled with the motor; and a processor operably coupled with the motorcontrol circuit, the processor comprising: at least one monitoring inputfor receiving a first signal indicating at least one of a rotationaldirection of a motor and a position of the motor; and at least onereporting output for transmitting a second signal indicating at leastone of the rotational direction of the motor and the position of themotor, wherein the processor is configured to transmit the second signalto a main controller at a rate that is less frequent than a rate foradjustments of the first signal.
 2. The motor system of claim 1, whereinthe processor is configured to transmit the second signal to the maincontroller responsive to an interrupt event.
 3. The motor system ofclaim 1, wherein the processor is configured to transmit the secondsignal at a conclusion of a predetermined cycle of the adjustments ofthe first signal.
 4. The motor system of claim 1, wherein thepredetermined cycle of the adjustments is determined by combinationlogic states of a pair of quadrature signals for the first signal. 5.The motor system of claim 1, wherein the processor further comprises: atleast one command input for receiving at least one system command fromthe main controller; and at least one control output for transmitting atleast one motor control signal to the motor control circuit responsiveto the at least one system command.
 6. The motor system of claim 5,wherein the at least one system command includes at least one of an“open” control signal, a “close” control signal, and a “brake” controlsignal for a movable partition driven by the motor.
 7. The motor systemof claim 5, wherein the at least one motor control signal comprises atleast one pulse width modulation signal to adjust a rotational speed ofthe motor.
 8. The motor system of claim 5, wherein the processor isfurther configured to temporarily operate the motor at a relativelyslower rate before stopping the motor and upon startup of the motorrelative to a steady state operation of the motor.
 9. The motor systemof claim 1, wherein the motor is operably coupled to the motor controlcircuit in an H-bridge configuration.
 10. The motor system of claim 9,wherein the motor control circuit comprises transistors as switchingelements of the H-bridge configuration.
 11. The motor system of claim 1,wherein the motor is operably coupled with a movable partition andconfigured to drive the movable partition along a track of a movablepartition system.
 12. A method of controlling a motor, the methodcomprising: monitoring adjustments in a signal indicating at least oneof a rotational direction and a position of a motor; reporting at leastone of the rotational direction and the position of the motor to a maincontroller of a motor control system at a rate less frequent than a rateof the adjustments of the signal; and controlling movement of the motorwith a plurality of motor control signals in response to control signalsreceived from the main controller.
 13. The method of claim 12, whereincontrolling movement of the motor with the plurality of motor controlsignals comprises transmitting a plurality of pulse width modulationsignals to a motor control circuit controlling the motor.
 14. The methodof claim 13, wherein transmitting the plurality of pulse widthmodulation signals to the motor control circuit comprises adjusting arotational speed of the motor during a start up mode and a stop mode ofthe motor.
 15. The method of claim 12, wherein controlling movement ofthe motor with the plurality of motor control signals comprisestransmitting a plurality of switching signals to a plurality ofswitching elements coupled with the motor in an H-bridge configuration.16. The method of claim 12, wherein reporting the rotational directionand the position of the motor to the main controller of a motor controlsystem at a rate less frequent than a rate of the adjustments of thesignal includes adjusting an internal count from the adjustments of thesignal more frequently than an external count signal that is transmittedto the main controller.
 17. The method of claim 16, wherein reportingthe rotational direction and the position of the motor to the maincontroller of a motor control system at a rate less frequent than a rateof the adjustments of the signal includes transmitting the externalcount signal to the main controller after a complete rotational cycle iscompleted for the internal count.
 18. The method of claim 12, whereinreporting the rotational direction and the position of the motor to themain controller of a motor control system at a rate less frequent than arate of the adjustments of the signal includes transmitting an externalcount signal in response to the main controller requesting a status ofthe motor from a processor.
 19. A method of installing a motor controldevice, the method comprising: positioning a motor, a motor controlcircuit, and a main controller to interface with a processor; operablycoupling a control output of the processor to the motor control circuit,the control output configured to transmit at least one motor controlsignal to the motor control circuit; configuring a monitoring input ofthe processor to receive a first signal indicating at least one of arotational direction of a motor and a position of the motor; operablycoupling a reporting output of the processor to the main controller,configuring the processor to transmit a second signal through thereporting output to the main controller at a rate less frequent than arate of adjustments of the first signal, the second signal indicating atleast one of the rotational direction of the motor and the position ofthe motor.
 20. The method of claim 19, wherein operably coupling thecontrol output of the processor to the motor control circuit comprisescoupling the processor to the motor control circuit in a configurationthat enables the at least one motor control signal to drive the motor ata reduced rotational speed of the motor during at least one of a startupof the motor and a period of time before stopping the motor.
 21. Themethod of claim 19, further comprising operably coupling a portion of amovable partition to the motor to enable the motor to displace themovable partition.
 22. The method of claim 19, wherein configuring themonitoring input to receive the first signal comprises configuring themonitoring input to receive a pair of quadrature signals from an encoderoperably coupled to the motor.
 23. The method of claim 19, whereinconfiguring the processor to transmit a second signal to the maincontroller at a rate less frequent than a rate of adjustments of thefirst signal comprises configuring the processor to transmit the secondsignal responsive to completion of a combinational logic cycle of thepair of quadrature signals.
 24. The method of claim 19, whereinconfiguring the processor to transmit a second signal to the maincontroller at a rate less frequent than a rate of adjustments of thefirst signal comprises configuring the processor to transmit the secondsignal responsive to receiving a status request signal from the maincontroller.
 25. The method of claim 19, wherein configuring theprocessor to transmit a second signal to the main controller at a rateless frequent than a rate of adjustments of the first signal comprisesconfiguring the processor to transmit the second signal responsive to aninternal count of the processor reaching a predetermined status.